Step 1: Materials
White footed pajamas (choose one that does not have snaps down the middle)
Blue iron-on reflective tape (1" x 60")
Needle and thread
Iron and ironing board
The following items were ordered from SparkFun:
EL Sequencer (SKU: COM-09203)
SparkFun Project Case - Black (SKU: WIG-08601)
Polymer Lithium Ion Batteries - 1100mAh (SKU: PRT-00339)
10 Jumper Wire - JST Black Red (SKU: PRT-08670)
Transceiver nRF24L01+ Module with Chip Antenna (SKU: WRL-00691)
Nordic FOB (SKU: WRL-08602)
LiPoly Charger - Single Cell 3.7-7V Input (SKU: PRT-00726)
FTDI Basic Breakout - 3.3V (SKU: DEV-08772)
The following items can be found at CooLight:
20 feet 3.2mm LYTEC - UM - UltraMarine (http://www.CooLight.com/category-s/54.htm)
IFW 3294 2K 3v
Step 2: Design
wire to buy.
You can start by simply sketching some designs on a piece of paper. Next, use pieces of string to lay the designs out on the pajamas. This will help you determine how long each segment of reflective tape will need to be.
Step 3: Adding the Reflective Tape
Step 4: Making the El-Wire
1) A power source
2) The El Sequencer
3) A strand of El-Wire
The first thing that you really need to assemble is the El-Wire.
Online you can find a number of tutorials on how to solder El-Wire. The most professional approach seems to be to use foil tape. The two "angel" wires get bent back and soldered onto the foil tape which is wrapped around the wire casing. I didn't use foil tape, but it would help to make the connection more durable. Instead, I followed the approach used by SparkFun on one of their El-Wire projects.
You can see in this picture the center wire covered in phosphor and the angel wires. You should use shrink tubing on both wires so that you keep some isolation and provide extra strength.
Just like they did at Sparkfun, you should put an outer shrink wrap on it too.
The El Sequencer has JST connectors for both the power sources and the El-Wires. Because the El-wire is AC, it doesn't matter which wire you connect to which. I tried to keep it consistent and put the black wire to the center.
Lastly, you need to solder two JST connectors onto the inverter. I used the IFW 3294 2K 3v inverter from coollight.com. Make sure to get the DC power going into the inverter correct. The AC power coming out doesn't matter. As I mentioned before, I like to keep all of the connectors consistent and would recommend that you do the same.
Step 5: Testing the El-Sequencer
I used a 3.3V Ftdi basic board to put the code on the the AVR. The El sequencer uses at Atmega168v. I used Avrdude set to connect to an AVRISP2 to download the code to the board. A bonus is that the board is powered from the Ftdi basic board as well. The first test should light up the wire like so.
A video of the same first run follows. Now you are finally getting somewhere!!!
Step 6: Programming
For the purposes of this costume, I wanted to have two different modes. One that I call flutter that makes the links strobe and another called twinkle that makes the lines blink sequentially. Both routines are actually very similar, the delay between powering the different lines is the only thing that really changes.
The more complicated step was to add the wireless control. The El-sequencer has a built in port for plugging in a Nordic RD link. I thought that adding a remote control would round out the effect. First, you need to download the NRF24L01 library from the following Sparkfun tutorial.
I would also look at the El-Sequencer code from the same page. Keep in mind that the schematics have changes from 1.0 when that tutorial was built to 1.2 now. The calls need to be modified to reflect the newer version of the El-Sequencer.
On the other end of the wireless link, I used a Nordic Fob. It gave me 5 buttons with different commands that would be sent over the wireless link. Using the Nordic chips is actually pretty simple. Once you get the timing right, one chips essentially sends a 3 element array over to the other device. In this case, each of the five buttons sent a different value in the second slot of the array. I built a loop that would read the wireless register in a loop. When it picked up a signal, it would fire off the routine that mapped to the button that was pressed.
Step 7: Powering the Costume
Just like the El-Wire and the inverters, you'll need to solder a JST connector onto it. Its quite simple to do, and you should be a pro by now.
The other side to the equation is that you need to be able to charge the battery. I decided to use the li-poly charger from Sparkfun, but not mount it in the device. Since this was a one time use costume, I didn't plan on recharging it frequently. If you already have a way to charge li-poly batteries, you don't need to purchase the one from the materials page.
Step 8: Packaging It Up
The black Sparkfun case displayed below worked very well. It was easy to mount all of the pieces. You need to leave enough El-Wire hanging out to position the project case in a convenient location. We used an extra 2 feet of wire so that it could be draped over our back when holding him in the costume.
The last thing that you need to do is add a switch to the battery. If you don't add a switch, you won't be able to turn off the device without unplugging the battery. I picked up a cheap SPST switch from Radio Shack. Any switch that can carry the DC 3.7V should work well.